fix final configuration reinit for exact exchange

exacti-exchange variables were not correctly initialized
when, at the end of variable-cell optimizations, a last check-computation
is done starting from the new cell vectors.

PW/src/exx_base.f90

@@ -529,10 +529,14 @@ MODULE exx_base
     REAL (dp) :: ft_(3), eps2 = 1.0d-5
     !
     nxxs = nr1x*nr2x*nr3x
-    IF(.not. allocated(rir)) ALLOCATE(rir(nxxs,nsym))
+    IF(.NOT. ALLOCATED(rir)) THEN   
+        ALLOCATE(rir(nxxs,nsym))
+    ELSE IF ((SIZE(rir,1) .NE. nxxs) ) THEN 
+        DEALLOCATE (rir) 
+        ALLOCATE (rir(nxxs,nsym))  
+    END IF  
     rir = 0
     ispresent(1:nsym) = .false.
-
     DO ikq =1,nkqs
        isym = abs(index_sym(ikq))
        IF (.not. ispresent(isym) ) THEN
@@ -554,12 +558,14 @@ MODULE exx_base
           ft_(2) = ft(2,isym)*nr2
           ft_(3) = ft(3,isym)*nr3
           ftau(:) = NINT(ft_(:))
+
           IF ( abs (ft_(1) - ftau(1) ) / nr1 > eps2 .or. &
                abs (ft_(2) - ftau(2) ) / nr2 > eps2 .or. &
                abs (ft_(3) - ftau(3) ) / nr3 > eps2 ) THEN
              CALL infomsg ('exx_set_symm',' EXX smooth grid is not compatible &
                   & with fractional translation: change ecutfock')
           ENDIF
+          
           DO k = 1, nr3
              DO j = 1, nr2
                 DO i = 1, nr1

PW/src/run_pwscf.f90

@@ -276,6 +276,8 @@ SUBROUTINE reset_gvectors ( )
   USE fft_base,   ONLY : dfftp
   USE fft_base,   ONLY : dffts
   USE control_flags, ONLY : lbfgs, lmd
+  USE funct,         ONLY : dft_is_hybrid
+  USE exx_base,      ONLY : exx_grid_init, exx_mp_init, exx_div_check
   IMPLICIT NONE
   !
   WRITE( UNIT = stdout, FMT = 9110 )
@@ -302,6 +304,12 @@ SUBROUTINE reset_gvectors ( )
   dffts%nr1=0; dffts%nr2=0; dffts%nr3=0
   !
   CALL init_run()
+  IF ( dft_is_hybrid() ) THEN
+     CALL exx_grid_init(REINIT = .TRUE.)
+     CALL exx_mp_init()
+     CALL exx_div_check()
+  ENDIF
+
   !
 9110 FORMAT( /5X,'A final scf calculation at the relaxed structure.' )
 9120 FORMAT(  5X,'The G-vectors are recalculated for the final unit cell'/ &

PW/src/wfcinit.f90

@@ -181,6 +181,7 @@ SUBROUTINE init_wfc ( ik )
   USE mp_bands,             ONLY : intra_bgrp_comm, inter_bgrp_comm, &
                                    nbgrp, root_bgrp_id
   USE mp,                   ONLY : mp_bcast
+  USE funct,                ONLY : dft_is_hybrid, stop_exx
   !
   IMPLICIT NONE
   !
@@ -299,6 +300,7 @@ SUBROUTINE init_wfc ( ik )
   !
   ! ... subspace diagonalization (calls Hpsi)
   !
+  IF ( dft_is_hybrid()  ) CALL stop_exx() 
   CALL start_clock( 'wfcinit:wfcrot' ); !write(*,*) 'start wfcinit:wfcrot' ; FLUSH(6)
   CALL rotate_wfc ( npwx, ngk(ik), n_starting_wfc, gstart, nbnd, wfcatom, npol, okvan, evc, etatom )
   CALL stop_clock( 'wfcinit:wfcrot' ); !write(*,*) 'stop wfcinit:wfcrot' ; FLUSH(6)